In many agricultural tillage operations, it is desirable to maintain the ground engaging implement a fixed distance beneath the soil surface. One example of this can be found in planter row units which employ a pair of forward discs arranged in a "V" configuration to form a furrow in the soil in which seeds are deposited. Depth gauge wheels are positioned aft of the furrow forming discs to limit the depth of the seed furrow formed by the discs. Seeds are periodically deposited in the furrow through a seed tube typically disposed aft of the furrow forming discs and between the gauge wheels. A pair of trailing furrow covering wheels, or discs, close the seed furrow after the seeds have been deposited in the furrow. The depth at which the seeds are deposited is important for future plant growth. The depth gauge wheels are thus an important element in the planting procedure. A problem can arise during wet, muddy conditions when soil residue adheres to the gauge wheels causing the seeds to be deposited at an improper soil depth and even sometimes on the surface of the soil. This may have an adverse affect on subsequent plant growth and may even result in failure of the plant to grow.
Various approaches have been adopted to maintain the gauge wheels clean of soil residue for proper depth control of the implement. In many installations, a scraper is maintained in closely spaced position from the periphery of the gauge wheel by attaching the scraper by suitable linkage to a support arm for the gauge wheel. A U-clamp with bolts typically is used to attach the scraper linkage to the gauge wheel's support arm. This mounting arrangement has led to problems because the gauge wheel support arm is typically tapered and results in the U-clamp working its way loose and improper positioning of the scraper element. An example of this type of installation for a paddle-type scraping wheel is shown in U.S. Pat. No. 5,443,125. Another arrangement where the scraper element is mounted to the planter frame is disclosed in U.S. Pat. No. 285,184. Other approaches attach the scraper element to the axle or hub of the gauge wheel such as shown in U.S. Pat. Nos. 1,074,763; 2,571,285; 5,269,380; and 5,431,233. All of these latter approaches employ complicated mounting linkage for the scraper element which limits the positioning flexibility of the scraper element relative to the gauge wheel and does not render the position of the scraper element dependent only upon the position of the gauge wheel.
The present invention addresses the aforementioned limitations of the prior art by providing a gauge wheel scraper arrangement wherein a scraper plate is maintained in fixed, closely spaced relation from an aft portion of the gauge wheel's periphery. The scraper is attached to a scraper support arm which, in turn, is coupled to a gauge wheel support arm causing the gauge wheel and scraper to move in unison as the gauge wheel is displaced vertically as it traverses a field to maintain the scraper in fixed position relative to the gauge wheel periphery.